Operating mechanisms for electric switches



March 24, 1942. G MEUEF; 2,277,555

OPERATING MECHANISM FOR ELECTRIC SWITCHES Filed July 26, 19 40 3 Sheets-Sheet 1 45 v v a: L H 44 -15 March 24, 1942; e. .1. ME-UER OPERATING MECHANISM FOR ELECTRIC SWITCHES Filed July 26,' 1940 3 Sheets-Sheet 2 I so 41/ oo oo 51 March 24, 1942. G. J. MEUER OPERATING MECHANISM FOR ELECTRIC SWITCHES 3' Sheets-Sheet 3 Filed July 26, 1940 Patented Mar. 24, 1942 OPERATING MECHANISMS FOR ELECTRIC SWITCHES George .I. Meuer, Milwaukee, Wis., assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a 'corporation of Delaware Application July 26, 1940, Serial No. 347,600

13 Claims.

This invention relates to improvements in operating'mechanisms,for'electrlc switches.

A primary object of the invention is to provide novel mechanical interlocking means for the operating elements of a plurality of electric switches, whereby operation of each of said switches to complete its associated'circuit is prevented pending operation of another of the switches to interrupt its associated-circuit.

Another object is to provide a switch mechanism of the aforementioned-character involving use of two electric switches each of which is normally biased to its off position.

Another object is to provide such a switch mechanism having operating elements of the pushbutton type.

Another object is to provide novel means for mounting and enclosing a switch mechanism of the aforementioned"character, to afford a unitary control station of the pendant pushbutton type.

Another object is to provide such .an interlocked pushbutton control station enabling use of a pair of like switches most of the elements of which may be of standard construction.

Another object is to provide a pendant pushbutton control station of "the aforementioned character adapted for control of either direct current or alternating current circuits, depending upon the particular type of :switches employed.

Another object is to provide a metal enclosing casing which is unequally divided longitudinally, the large section of said casing having means to facilitate attachment of the switch mechanism thereto :as :a unit and means'to guide the respectiveoper-ating elements of the switches.

Another object is to provide a novel form and arrangement of the switch terminals to facilitate attachment of the circuit wires after assembly of the switch mechanism with respect to the main section of the casing.

Another and more specific object is to provide a pendant pushbutton control station having a switch mechanism -of the double-pole, doublethrow type.

Another object is to provide novel means for grounding the metal enclosing casing.

Another object'is to provide a pendant pushbutton control station wherein eachpushbutton operating element is of the manual hold down type.

Another and more'speclfic object is to provide 'a manual reversing station for control of a, mo-

tor operated hoistor the like.

Other objects andadvantages of the invention will hereinafter appear.

The accompanying drawings illustrate several embodiments of the invention which will now be described, it being understood that the embodiments illustrated are susceptible of modification in respect of certain structural details thereof without departing from the spirit of my invention or the scope-0f the appendedclaims.

In the drawings, Figure 1 is a side elevational view (full size) of a pair of mechanically united and mechanically interlocked switches forming the reversing switch mechanism, the metal enclosing casing being shown in central longitudinal section, the on position of one'of the pushbuttonsand its associated switch actuating element being shown in dotted lines.

Figure 2 is .a bottom plan view of the pendant pushbutton control station illustrated in Fig. 1,

the metal cover of the casing being removed.

Fig. 3 is a fragmentary view similar to Fig. 1, but with one switch shown in longitudinal section, and with its operating button depressed.

Fig. 4 is a side 'elevational view '(fullsize) of a reversing switch mechanism of relativelygreater current controlling capacity than that illustrated in Figs. 1 to 3, the pivoted lever providing the mechanical interlock between the switch operating elements being shown in section-and the twopart metal enclosing casing beingshown in longitudinal section.

Fig. 5 is a'top plan view of the switches assembled with respect to the supporting plate, which plate is adapted for releasable attachment to the large section of the enclosing casing.

Fig. '6 is a view in section of the casing, on the broken line 6-6 of Fig. 4, showing in elevation the end of the left-hand switch of Fig. 4, the operating pushbutton of said switch being shown depressed in full lines and in its normal position in dotted lines.

Fig. 7 is a detail perspective view of the mechanical interlocking lever of the switch mechanism, the biasing leaf spring being shown attached thereto.

Fig. 8 is a central longitudinal section through the large section of thecasing and through one of the switches, illustrating another modified form of mechanical interlock for the pair of switches, the switches illustrated being particularly adapted for control of alternating current.

Fig. 9 is a top plan view of the supporting plate with thepair of switches attached thereto, showing the interlocking lever associated with the pushbuttons and the biasing springs associated with said lever.

Fig. is a sectional view, on the line iii-10 of Fig. 8.

Fig. 11 is a perspective View of the interlocking lever shown in Figs. 8 and 9, and

Fig. 12 is a fragmentary view, partly in section on the line 12-42 of Fig. 8, illustrating the means employed in each of the two switches for normally biasing the same to off position.

Referring first to the form of pendant pushbutton reversing station illustrated in Figs. 1 to 3, the numeral 15 designates the front or larger section of a cast metal enclosing casing, the smaller rear section or cover of said casing being designated by the numeral [6. The cast sections 15 and IE of the casing are recessed, as best illustrated in Fig. 1, to provide a relatively thinwalled structure of adequate strength.

To provide for releasable attachment of the casing sections to each other, the section I5 is provided at four symmetrically arranged points with enlargements or posts l1, l8, l9 and formed integrally with the side walls thereof, said posts being recessed, preferably by the casting operation, and tapped to receive the shanks of securing screws, two of which are shown in dotted lines at 2|, 2| in Fig. 1. Section 16 is provided with four correspondingly arranged integral posts, two of which are shown at 22 and 23 in Fig. l, the posts last mentioned being provided by the casting operation with openings providing clearance for the shanks of said screws 2|. Also, as indicated by dotted lines in Fig. 1, section 18 is provided in its outer surface with countersinks to accommodate the heads of said screws 2|.

Section 15 is provided in one end wall thereof with a circular opening 24 through which a conductor cord (not shown) may be inserted for attachment of the wires thereof to the respective switch terminals. In practice the portion of the end wall surrounding said opening 24 is made relatively thick to provide for attachment thereto of any well known form of metal cord grip or clamp (not shown) to provide a strain relief for the wires attached to the switch terminals. The conductor cord may, of course, be of the metalor rubber-armored type to provide adequate support for the pushbutton station, which is preferably of the pendant type.

Section [5 is further provided on its opposite side walls with four symmetrically arranged posts 25, 26, 21 and 28 the flat faces of which form ledges located in a common plane olTset inwardly from the edge l5 at the open end of said section. Posts 25 to 28 are provided with recesses (not shown) which are tapped to receive .ie shanks of a corresponding number of screws 29, which serve to secure within said section a metal supporting plate 30 for the pair of switches employed. Section 15 is provided at longitudinally spaced points with two pairs of integral, laterally spaced ribs or struts 3|, 32 and 33, 34, the adjacent opposed edges of which pairs of ribs act as guide surfaces for inverted channelshaped metal members 35, which are attached to the pushbuttons 36, 35 associated with the respective switches employed in the combination. The front wall l5 of section I5 is provided with circular openings 15 and 15 to permit reciprocontrolling capacity 01 ten amperes direct current. Said switches are in general of the character disclosed and claimed in my Patent No. 1,889,259, dated November 29, 1932, and in my Patent No. 1,977,678, dated October 16, 1934, to which reference may be had for a more detailed explanation of the construction and mode of operation of such switches.

As indicated by the section in Fig. 3, each switch comprises essentially a molded insulating base having a recess opening to the upper end thereof, the bottom wall of the recess having a central rib upon the flat surface 31 of which a flat insulating contactor-carrier 31 is adapted to slide. Carrier 31 has attached thereto, on opposite sides of said rib, a pair of contactors each having portions thereof exposed on opposite faces of the carrier, one of the contactors being designated by the numeral 31.

Said contactors are adapted for movement thereof jointly into and out of bridging engagement with pairs of upper and lower resilient contacts, the upper contact of one pair being designated by numeral 31 The means for effecting snap movement of the contactors into and out of bridging engagement with the pairs of contacts comprises an insulating member .11 having a lost motion driving connection with the Walls of an opening 31 in carrier 31 said member 31 being pivotally supported by a U-shaped wire member or yoke 31 the opposite arms of which are pivotally engaged with openings provided in a boss 31 formed on the metal top plate 31 as shown at 31 in the upper switch of Fig. 3. Each switch is provided with an insulating top plate 31".

A coiled compression spring 31 is interposed between member 31 and the end 313 of a toggle lever 38, which is here shown as of special form. Thus lever 38 is pivoted by a pin 39 within a hollow bushing which is rigidly and non-rotatably attached to boss 31 in the manner indicated in Fig. 3. The upper, initially closed, end of bushing 40 is provided with a saw-cut or kerl in its top and sides (see Figs. 3 and 5) to pro vide clearance for the arms 33 and 38 of the lever 38 upon oscillatory movement of the latter.

Arm 38 of said lever is provided with an open ing 38 of substantially elliptical form to accommodate a headed pin 4| the shank of which penetrates alined openings in the opposite side walls of member 35, the shank end of said pin being enlarged or upset, as shown at M in Fig. l, to retain the same in assembled relation.

The end of lever arm 33 is formed as shown at 33 said end (in respect of the left-hand lever of Fig. 1 and the corresponding upper lever of Fig. 3) being primarily adapted for cooperation with member 35 of the other switch of the com bination to provide a mechanical interlock between the two pushbuttons 3!; so that either of the pushbuttons 36 may be depressed to an extent suilicient to effect closure of the contacts of its associated switch (as indicated by dotted lines in respect of one switch in Fig. l, and as indicated in respect of the other switch in Fig. 3), but both pushbuttons may not be simultaneously depressed to an extent sufilcient to effect closure of the contacts of both switches.

Thus as shown in dotted lines in Fig. 1 upon depression of the left-hand pushbutton 35 the end 38 of the lever arm 38 associated therewith is tilted or rotated in a counterclockwise direction into engagement with the horizontal portion of the member 35 associated with the other pushbutton, thus preventing manual deprcssion of the latter. Similarly, with reference to Fig. 3, upon depression of the lower pushbutton the member 35 is. so positioned withre'spect to the end 38 of the lever arm 38 associated with the upper switch as to prevent depressionof the upper pushbutton.

In practice the members 35 attached to the respective pushbuttons cooperate with the inner surface of the wall I of section I5 to limit the extent of upward or outward movement of the pushbuttons with respect to the enclosing casing. However, 'the'ends 38 of the respective lever arms 38 are adapted to abut against the supporting plate to limit the extent of upward movement of the pushbuttons prior to assemblyof the combined switch unit with respect to casing section I5, thus insuring maintenance of the various switch operating parts in assembled relation to plate 30.

The pushbuttons 36 are additionally guided, or limited to straight-line reciprocating movement, by a pair of like pins 42, 42, the fiat ends of the conical head portions 42 of which are adapted to seat against the flat insulating cover plates of the respective switches, the metal supporting plate 30 having a pair of properly spaced openings 30 to accommodate portions of the heads 42, and the shanks of said pins extending to a plane substantially coincident with the inner surface of the wall I5 of section I5. Each pushbutton 36 is provided with a recess 36 of circular form in transverse cross section to provide for a relatively close sliding fit thereof with respect to the shank of pin 42. Each pushbutton 36 is also preferably provided with an integral extension 36 (Fig. 3) j of reduced size intransverse cross section, the arrangement being suchthat guiding of the pushbutton by its associated pin 42 is insured in all positions of the former. 7

Each pushbutton 36 is also biased to its outer extreme position, as by means of a coiled compression spring 43 which is interposed between supporting plate 30 and the upset flange 36 which rigidly secures member to its respective pushbutton. As shown in Fig. 3 each spring 43 surrounds its associated pin 42 and the reduced end portion 36 of the pushbutton associated therewith, the expanded and compressed conditions of the respective springs 43 being illustrated.

Inasmuch as the switches 37 as initially confor the shank of a steel screw '44 which acts to clamp said L-shaped member to the terminal. Lock washers 4'4 are preferably associated with the heads of screws 44 to prevent accidental loosening of the latter. Fig. 1, six of the auxiliary terminal members 45 are of like form and size, or thickness; whereas two of said auxiliary terminal members 46 are of relatively thinner stock and have perforated portions underlying the adj acent'o'r middle terminals of the pair of switches. The free end portions of terminal members 45 are tapped to accommodate the shanks of the usual brass binding screws 41,.six of which'are required in the complete combination. Thus it willbe apparent that As best illustrated in thetwo middle binding screws of the switchcombinati'on respectively provide a common electrical connection 'for one stationary contact of each switch. That is to say, upon depression of one pushbutton 36 the switch associated therewith is adapted to function to complete a given circuit (say, a hoist motor circuit for effecting operation thereof in one direction), whereas upon depression of the other pushbutton 36 (with a required release of the first pushbutton) a circuit will be completed for effecting reverse operation of the hoist motor (not shown).

In practice the section I5 of the casing is provided with an integral post or stud '48 having a binding screw 49 associated therewith and adapted for-clamping engagement with a grounding wire (not shown) which may form a part of the conductor which enters through opening 24 in section I5 of the casing.

The form or contour and ornamentation (not shown herein) of the complete switch unit constitute the subject matter of my Design Patent 121,962, granted August 13, 1940, for Design for a pendant electric switch.

The modified form of device illustrated in Figs.

'4 to 7 is in'generarquite similar to'that of Figs. 1

tain of the switch operating parts may be identical with those aforedescribedand "the same have been given corresponding numerals 'of reference. Thus, the pushbuttons 36, members 3 5, guide pins 42, springs 43, bushings 40 and pivot pins 39 and H may be structurally and functionally like those parts aforedescribed. 7

Similarly the casing section 52 is provided with two transversely alined pairs of guide rib-s, one pair being shown at 53,54 in Figs. 4 and 5. and 'one rib of the other pair being shown at 56 in Fig. 4, the spaced edges of which pairs of ,ribs cooperate with members 35 to assist in guiding the respective pushbuttons. Pushbuttons 36 are further guided by means of pins or studs 42, 42 and said pushbuttons are biased to the extreme positions thereof shown in Fig. 4 by the aforementioned springs 43. Pins "42 are associated with a metal support plate 51 to which the respective switches are attached as by means of pairs of screws or boltscertain of which are shown at 58 in Figs. 4and 5.

Plate 51 is preferably of rectangular contour, as shown in Fig. 5, and is provided with four symmetrically arranged openings 51*, 57 5! and 5 to accommodate the shanks of a corresponding number of screws 59 (see Fig. 6) which take into tapped openings provided in posts, certain of which are shown at 5|, 51*, 51 in Figs. 5 and '6, whereby said plate with its attached switches maybe secured to section-5| of the easing. The operating means for the respective switches comprise bell crank levers 60, the arm 60 'of each lever being pivotally connected with one of the members 35 as 'by means of the pin 4|, and'theother arm 60 (dotted lines, Fig, 4)

cooperates with its associated switch parts to effect circuit completing and interrupting operation thereof with a snap action. As will be understood, the hollow metal bushings 40 may be identical with those aforedescribed, the same having kerfs in the upper end thereof to accommodate the arms 60 of levers 60, which are pivotally supported as by means of pins 39, and to provide clearance for the arm [ill upon oscillation of the respective levers.

The means for providing a mechanical interlock between the pushbuttons 36 of the respective switches preferably comprises an interlock lever 6| the flat main body portion of which is pivotally attached to the support plate 51 as by means of the rivet stud 62, in the manner best illustrated in Fig. 4. Lever 61 is provided with end portions 6| and 61 of equal length bent upwardly at a right angle thereto, and portion 6 I has attached thereto, as by means of a rivet 63, a resilient metal member or leaf spring 64.

The free end portion of spring 64 is initially bent to extend inwardly at such an angle as to engage one end of the lower pivot pin 39 (Fig. 5) under a predetermined degree of compression or strain, whereby spring 64 acts to normally bias lever 6| to the full line position thereof illustrated in Fig. 5. As a result the end portion 61 of lever BI is positioned with an edge portion 6 I underlying the fiat lower surface of the upper pushbutton 36. However, the edge portion 61 is angled downwardly to form a cam surface, so that upon depression of said upper pushbutton 36 the peripheral lower edge of the latter engages the cam surface 61 to force lever 6| to rotate in a counterclockwise direction to the dotted line position thereof (Fig. against the bias of spring 64. Consequently the fiat upper edge Si of end portion 6| is positioned directly beneath the fiat under surface of the lower pushbutton 36 (Fig. 5) to positively prevent depression of the latter. Upon manual release of the upper pushbutton 36, spring 64 acts to automatically return lever 6| to the full line position thereof shown in Fig. 5.

Conversely, if the lower pushbutton 36 is first depressed (Fig. 5) to effect circuit-completing operation of its associated switch mechanism said pushbutton will be positioned in a relation to positively prevent counterclockwise rotation of interlocking lever 6|, wherefore the inclined or cam edge 6| of the portion 6| thereof will cooperate with the lower surface of the upper pushbutton 36 to positively prevent a substantial de gree of depression of the latter, thus preventing circuit-completing operation of the switch parts associated therewith. As best illustrated in Figs. 5 and '7, the lever 6| is preferably cut away at H to provide proper clearance between the same and the boss 56 forming a part of the metal top plate of the upper switch 50.

The left-hand switch (Fig. 4) is provided with four, and the right-hand switch is provided with two, bottom-wiring terminal members 65, the relatively long substantially vertical arms of said terminal members being preferably bent to the form thereof illustrated in dotted lines at 65 at the right-hand end of Fig. 4. Members 65 when formed as shown conform very closely to the contour of the outer surfaces of the end walls of the molded insulating bases of switches 50, thus providing a more rigid support for such members, improving the appearance of the switches, and affording a maximum utility of the integra1 insulating barriers between the terminal members at opposite ends of the respective switch bosses.

The horizontal portions of terminal members 65 are tapped to receive the shanks of binding screws 65, which in practice are substantially larger than the binding screws 45 of Figs. 1 to 3. Members 65 are secured in position by screws 61, which are preferably formed of steel and are of substantially larger size than the screws 44 of Figs. 1 to 3. Screws 61 may, of course, be provided with lock-washers (not shown) to prevent accidental loosening thereof. The two inner end terminal members of the right-hand switch of Fig. 4, one of which members is shown at 6B, are of relatively thinner stock than terminal members 65. The arms of members 68 are of substantially equal length and are bent at a right angle to each other, the vertical arm of each having an opening to provide clearance for the shank of its associated securing screw 61, and the horizontal arm of each having an opening to provide clearance for the shank of its associated binding screw 66.

The grounding terminal screw 49 is arranged in substantially the same manner described in connection with Figs. 1 to 3. The casing sections may, if desired, be ornamented in the manner disclosed in my aforementioned Design Patent No. 121,962. The section or cover 52 of the casing is secured to section 5| as by means of four screws, two of which are shown at 69 in Fig. 6, in the manner described in connection with Figs. 1 to 3. The elements not specifically described in connection with the device of Figs. 4 to 7 function in the same manner as set forth in the description of Figs. 1 to 3.

In the modified form of pendant pushbutton station illustrated in Figs. 8 to 12 I employ a pair of slow-make, slow-break switches 10, ID of the character disclosed and claimed in Patent No. 2,133,545, granted October 18, 1938, to A. W. Krieger. The switches shown (full size) in Figs. 8 to 12 are particularly adapted for control of alternating current circuits, for reasons set forth in said Patent No. 2,133,545, said switches having a rating of 15 amperes at 250 volts alternating current. The switches 10 of Figs. 8 to 12, which are of the three-pole type, differ in respect of certain structural details from the threepole switch shown in Figs. 1'? to 19 of said Patent No. 2,133,545.

More particularly, the disk or cylinder H (Figs. 8 to 10 hereof) is rotatably supported by a pin 12, which is in turn rotatably supported by the insulating plunger I3, the length of pin 12 and the form of plunger 13 being such that accidental lateral disassembly of said pin from disk 1| is positively prevented (see Fig. 10). Similarly the pairs of stationary contacts 14, 14 and the contactors 15 (see Fig. 8) have silver tips or buttons attached thereto, as by spot welding, as distinguished from the inlaid form of contact tips specifically disclosed in Patent No. 2,133,545. Moreover, each switch 10 is normally biased to its circuit interrupting position, as by means of a coiled compression spring 16, one end of which surrounds an extrusion or boss 11 formed upon a plate 18 which seats against an end wall of a recess formed in the upper section 19 of the insulating casing of the switch, the other end of spring 16 surrounding the end 80 and bearing against the shoulders 8| formed upon a composite metal yoke member, the spaced arm portions 82 and 83 of which (Figs. 8 and 12) have their ends notched to provide an open pivotal connection thereof with the opposite ends of a pin 84 which is rigidly attached to the switch lever 85, whereby the latter is normally biased to the position thereof illustrated at the righthand end of Fig. 8.

The structural details of the switches 10, including the details just mentioned, form no part of the present invention; and it is to be understood that other suitable forms of slow-make, slow-break switches may be utilized, provided that the same are so constructed as to normally effect operation of the parts thereof to circuit interrupting position.

The lever 85 of each switch I is pivotally supported by a pin 86 substantially in the manner of the toggle lever (56, Fig. 19) of Patent No. 2,133,545. As will be noted, however, the levers 85 are of special form, each comprising an arm 81 the perforated end of which is positioned within a kerf 88 in the lower end of the reduced portion 89 of a pushbutton 9,9. Said reduced portion 89 is provided with openings alined with each other and with the perforation in arm 81, a headed pin 9| having its shank extended through said openings and said perforation to provide a pivotal connection between each but,- ton 90 and its associated lever 85, the shank of said pin having its end upset, as indicated at 9| in Fig. 10, to permanently secure said parts in assembled relation.

Each lever 85 is also provided with an arm 92- having a hooked end 93 which penetrates alined openings in the metal supporting plate 94 (which is common to the two switches) and in the insulating top plate 95 (see Fig. 8) whereby the portion 95 of arm 92 is adapted to engage the upper surface of plate 94, to limit the degree of clockwise rotation of lever 85 (and consequently the degree of upward displacement of the pushbutton 90 associated therewith) under the bias of spring 16. Under these conditions cam portion 91 of lever 85 acts upon cylinder II to depress plunger 13 and the contactors I to effect circuit interruption.

Upon depression of either pushbutton 90 (as shown in dotted lines at the left-hand side of Fig. 8) the lever 85 associated therewith is rotated counterclockwise, so that its cam portion 91 acts to permit upward movement of cylinder TI and the plunger 13 andcontactors I5 associated therewith, under the bias. of springs 98, thus completing the circuit controlled by that particular switch.

Each switch is provided with six bottom wiring terminal elements, the binding screws of which are designated by the numerals 99' (Fig. 8) In accordance with my invention the longitudinally adjacent terminals of the two switches are electrically connected, as by means of three flat bus members orv conductor plates, one of which is shown at I00 in Fig. 8. The bus members I00 are perforated at opposite ends thereof to accommodate the shanks of the intermediate binding screws 99, whereby the bus members are clamped in assembled position by the heads of said binding screws. As will be apparent, only one of the two screws associated with each bus member is utilized for attachment of the circuit wire common thereto.

Supporting plate 94 is preferably of the form best illustrated in Fig. 9, the same having two pairs of tapped openings, diagonally spaced from each other, to accommodate the shanks of bolts IOI by which the assembled switches are attached thereto. Plate 94 is provided with four symmetrically arranged openings 94 94 94 and 94 to accommodate the shanks of screws (not. shown) whereby plate 94 may be secured to-the relatively larger section I02 of the metal enclosing casing, the relatively smaller section (not shown) having a recess of suificient depth to provide ample clearance for the insulating bases of switches I0, and the same being attachable to. section I02 as by means of four screws or bolts, as described in connection with the other switching devices.

As shown in Fig. 8, the circular walls of openings I02 and I02 are made of substantial depth or. thickness to insure substantially straight-line reciprocating movements of pushbuttons with respect thereto. Also, as indicated by the dotted line illustration at the left-hand side of Fig. 8, the edge portion 92 of arm 92 is adapted to abut against the periphery of the pushbutton 90 associated therewith upon a given degree of depression of the latter, to thereby positively limit the degree of depression of the pushbutton and the degree of counterclockwise rotation of its associated lever 85. By the means aforedescribed proper operation of the parts of the switches individually is insured.

As in the forms of my invention heretofore described, it is necessary or desirable to insure against simultaneous completion of the circuits controlled by the two switches l0. Accordingly I provide a mechanical interlocking connection between the two pushbuttons '90, which connection is preferably in the form of a teetering bar or lever I03 of the character best illustrated in Fig. 11. Thus lever I03 consists of a onepiece. punched and stamped. sheet metal member having arms I03= and I03. extending upwardly at a predetermined relatively wide angle with respect to each other. In practice the arms I03 and I03 are united throughout their length by struts I03 and 13 produced from the one-piece blank by the stamping operation, thus insuring substantial rigidity or unyielding relationship of arms I03 and I03 with respect to each other.

Arms H13 I03 are cut away or notched at I03. and I03 to provide clearance between the same and the reduced portions 89. of pushbuttons 90, whereby the outer ends of said arms will respectively underlie the central portions of said pushbuttons. As shown in dotted lines in Fig. 8, member I03 is so arranged With respect to pushbuttons 90 that upon substantially full depression of either of the latter the arm 33 or I03 associated therewith is likewise depressed to a position parallel with and closely adjacent to the upper surface of plate 94, under which condition the other arm I93 or I039, as the case may be, is tilted upwardly to positively engage and restrain depression of the other pushbutton.

In order to retain member I03 in assembled relationship to the other parts without rattling, and to normally yieldably hold the two pushbuttons. 90 in their upper extreme positions, to prevent possible rattling at the pivotal connections 9| (Fig. 8) I provide a pair of leaf springs I04, I04, composed of phosphor bronze or other resilient metal, the ends I04 I04 of said springs being positioned fiatwise upon the upper surface of plate 94 and rigidly secured or fixed thereto, as by; spot-Welding. The main body portions of springs I04 are bent or angled upwardly, as shown at the left-hand end of Fig. 8 to normally respectively yieldably engage the under surfaces of the arms I03 and I03 of member I03, whereby the latter is held in the position thereof illustrated in full lines in Fig. 8. As shown. the arm I03 is provided with a slot or opening I03 to provide clearance for the arm92 and hooked end E3 of the lever 85 associated with the left-hand switch in Fig. 8.

As illustrated in Figs. 8 and 9, plate 94 is provided with lugs 94 94, 94 and 94 partially sheared and bent downwardly therefrom for engagement with vertical end grooves in the upper sections I9, 19 of the switch bases, to assist in restraining lateral movement thereof with respect to plate 94. A grounding terminal screw I05, of the character described in connection with the other devices, is also preferably provided. As illustrated in Fig. 10, plate 94 is preferably provided with pairs of downward extrusions or bosses 94 and 94 which penetrate corresponding pairs of openings in the respective insulating cover plates 95 and bear against the respective pivot pins 86 to more firmly retain the latter in the bearings or seats provided therefor in the top surfaces of the upper insulating sections 19 of the switch casings. As aforeindicated, the switching device of Figs. 8 to 12 is likewise adapted to serve as a pendant pushbutton station for reversing control of a hoist motor or the like.

What I claim as new and desire to secure by Letters Patent is:

1. In a pendant pushbutton control station for hoist motors and the like, in combination, a metal casing divided longitudinally in a plane parallel to the front face thereof, said front face of the casing having a pair of openings formed therein, a pair of structurally complete electric switch units of like form, a metal supporting member to which each of said switch units is rigidly secured, said supporting member being in turn secured to the front section of said casing, each of said switch units having a separately molded insulating base, a plurality of sets of stationary and movable contacts carried by each base, a switch operating lever pivotally supported relatively to each base, a single pushbutton element pivotally connected with each lever at a point offset from the point of pivotal support of the latter and extending through one of said casing openings, and mechanical interlocking means comprising a sheet metal member oscillatably attached to said supporting member and associated with said pushbutton elements to positively insure against simultaneous depression of the pushbuttons to degrees suflicient to effect operation of the switch mechanisms associated therewith, while providing for depression of either of said pushbuttons singly, each of said levers having spring means individual thereto to normally bias the same and its associated pushbutton in a direction to effect circuit interrupting operation of the respective switch mechanism.

2. In a pushbutton control station, in combination, a manually operable switch assembly comprising, a metal member, a pair of multipole switches of like form secured to the lower surface of said metal member, each of said switches having a single pivoted operating lever extending upwardly beyond said metal member, a pair of pushbuttons each pivotally connected with one of the respective levers in offset relation to the point of pivotal support of the latter, spring means associated with the respective levers to normally bias each of the same to a given extreme position forwardly of the front surface of said metal member to provide for olf positioning of its associated switch mechanism, means including said levers cooperatively associated with said pushbuttons to positively prevent simultaneous depression thereof to their in ner extreme positions, for the purpose set forth, and means comprising a cover member to which said metal member is rigidly attached, said cover member having openings to accommodate said pushbuttons and to assist in restricting each of the same to reciprocating movements in a substantially straight line.

3. In a pendant pushbutton control station for hoist motors and the like, in combination, a metal casing divided longitudinally in a plane parallel to the front face thereof, a pair of electric switches of like construction rigidly secured to the front section of said casing, each of said switches having a separately molded insulating base, a plurality of sets of stationary and movable contacts carried by each base, a single pushbutton operating element associated with each base and extending therefrom through said front face of the casing, each of said operating elements including a lever pivotally supported relatively to the base, mechanical interlocking means comprising an oscillatably supported sheet metal member associated with said pushbutton operating elements to positively insure against simultaneous depression of the pushbuttons to degrees sufiicient to effect operation of the switch mechanisms associated therewith, while providing for depression of either of said pushbuttons singly, for the purpose set forth, a coiled compression spring associated with each lever to bias the respective pushbutton out of its depressed position, and said switches having wiring terminal elements exposed at the rear thereof to facilitate wiring of said switches after the latter are secured to said front section of the casing.

4. In a switch mechanism for reversing control of hoist motors and the like, in combination, a hollow cast metal enclosing casing divided longitudinally to provide a front section of relatively great depth and a rear section of relatively small depth, said front section having a plurality of recessed and tapped posts formed integrally with the opposite side walls thereof and offset inwardly a substantial distance from the open end thereof, a flat sheet metal plate having openings alined with the recesses in said posts, a pair of electric switches of like construction rigidly attached to said plate in tandem relationship to each other, the insulating base portions of said switches being positioned at the rear face of said plate and the operating elements thereof being positioned forwardly of the front face of said plate, the operating elements of the respective switches each comprising a switch operating lever pivotally supported in a substantially central relation to the switch base and a single pushbutton pivotally connected with said lever in longitudinally offset relation to the center of the switch base, the front wall of said casing having openings to provide sliding clearance for the pushbuttons and to assist in guiding the latter, each of said pushbuttons having means asso ciated therewith to bias the same to its outer extreme position, mechanical interlocking means to insure against simultaneous depression of said pushbuttons to their respective inner extreme positions, and a plurality of screws penetrating said plate openings and engaging said tapped recesses to secure said plate and said switches to said front section of the casing.

5. In a switch mechanism for reversing control of hoist motors and the like, in combination, a hollow cast metal enclosing casing divided longitudinally to provide a front section of relatively great depth and a rear section of relatively small depth, said front section having a plurality ofv recessed and tapped posts formed integrally with the opposite side walls thereof and offset inwardly a substantial distance from the open end thereof, a fiat sheet metal plate having openings alined with the recesses in said posts, a pair of electricswitches of like construction rigidly attached to said plate in tandem relationship to each other, the insulating base portions of said switches being positioned at the rear face of said plate and the operating elements thereof being positioned forwardly of the front face of said plate, the operating elements of the respective switches each comprising a switch-operating lever pivotally supported in a substantially central relation to the switch base and a single pushbutton pivotally connected with said lever in longitudinally offset relation to the center of the switch base, the front wall of said casing having openings to provide sliding clearance for the pushbuttons and to assist in guiding the latter, each of said pushbuttons having means'associated therewith to bias the same to its outer extreme position, mechanical interlocking means to insure against simultaneous depression of said pushbuttons to their respective inner extreme positions, a plurality of screws penetrating said plate openings and engaging said tapped recesses to secure said plate and said switches to said front section of the casing, each of said pushbuttons having an inverted channel-shaped metal member rigidly attached thereto and adapted to limit the degree of outward movement thereof, and said front section of the casing having pairs of transversely spaced ribs formed integrally therewith and cooperating with said inverted channel-shaped members to restrain said pushbuttons against rotary movement and to assist in limiting the same to reciprocating movement in a straight line.

6. As an article of manufacture, a hollow switch casing comprising two cast metal sections, the front section being relatively deep and the rear section being relatively shallow, said front section having a pair of longitudinally spaced openings formed in the front wall thereof to provide slidable clearance for pushbutton operating elements of suitable form, said front section having a plurality of recessed and tapped posts formed integrally with the opposite side walls thereof and offset inwardly from the open end thereof to provide a ledge for attachment of a multiple switch supporting plate of suitable form, said front section also having a plurality of recessed and tapped posts formed integrally with the opposite side walls thereof and arranged in a substantially flush relation to said open end, the rear section of said casing having openings alined with said posts last mentioned to provide clearance for the shanks of screws employed to releasably secure the casing sections in assembled relation, said front section having pairs of transversely spaced ribs formed on the opposite side walls thereof and offset inwardly from the plane of the ledge formed by said posts first mentioned, and each pair of ribs being adapted to cooperate with an element of a pushbutton to restrain the latter against rotary movement and to assist in limiting the latter to reciprocating movement in a straight line.

'7. As an article of manufacture, a manually operable reversing switch assembly of the pushbutton type comprising, a relatively long, flat sheet metal plate having a pair of longitudinally spaced openings formed therein, a pair of multipole switches of like form secured to said plate in tandem relationship to each other, said switches having insulating base portions arranged at the rear face of said plate and pivotally supported operating levers extending upwardly through said plate openings and having portions thereof exposed atthe front face of said plate, a pushbutton pivotally connected with each lever in longitudinally oflsetrelation to the point of pivotal support of the latter, spring means associated with each pushbutton to normally bias the same to a given extreme position forwardly of the front face of said plate, and means cooperatively associated with said pushbuttons to positively prevent simultaneous depression thereof to their inner extreme positions, for the purpose set forth.

8. As an article of manufacture, a manually operable reversing switch assembly of the pushbutton type comprising, a relatively long fiat sheet metal plate having a pair of longitudinally spaced openings formed therein, a pair of multipole switches of like form secured to said plate in tandem relationship to each other, said switches having insulating base portionsarranged at the rear face of said plate and pivotally supported operating levers extending upwardly through the respective plate openings and having portions thereof exposed at the front face of said plate, a pushbutton pivotally connected with each lever in longitudinally offset relation to the point of pivotal support of the latter, spring means individual to each pushbutton to normally bias the same to its extreme position forwardly of the, front face of said plate, and means ineluding an arm formed integrally with one of the switch levers and an element associated with the pushbutton of the other switch to insure against simultaneous depression of the pushbuttons to their inner extreme positions respectively, for the purpose set forth.

9. As, an article of manufacture, a manually operable, reversing switch assembly of the pushbutton type comprising, a relatively long, fiat sheet metal plate having a pair of longitudinally spaced. substantially circular openings formed therein, a pair of double-pole, two-position, snap switches of like form. secured to said plate in tandem relationship to each other, said switches having insulating base portions arranged at the rear face of said plate and pivotally supported operating levers extending upwardly through said plate openings and having portions thereof exposed at the front face of said plate, a pushbutton pivotally connected with each lever in longitudinally offset relation to the point of pivotal support of the latter, said switches being of the spring toggle type whereby the same are normally biased individually to either the on or the off position thereof depending upon the positions of their respective levers, overpowering spring means associated with each pushbutton to normally bias the same and its associated lever to a given extreme position to provide for off positioning of its respective switch, each of said pushbuttons being normally adapted upon depression thereof to its inner extreme position to provide for operation of its associated switch to on position, and means for mechanically interlocking said pushbuttons to positively prevent simultaneous depression thereof to their inner extreme positions.

10. As an article of manufacture, a manually operable reversing switch assembly of the pushbutton type comprising, a relatively long, fiat sheet metal plate having a pair of longitudinally spaced substantially circular openings formed therein, a pair of double-pole, two-position, snap switches of like form secured to said plate in tandem relationship to each other, said switches having insulating base portions arranged at the rear face of said plate and pivotally supported operating levers extending upwardly through said plate openings and having portions thereof exposed at the front face of said plate, a pushbutton pivotally connected with each lever in longitudinally offset relation to the point of pivotal support of the latter, said switches being of the spring toggle type whereby the same are normally biased individually to either the on or the off position thereof depending upon the positions of their respective levers, overpowering spring means associated with each pushbutton to normally bias the same and its associated lever to a given extreme position to provide for off positioning of its respective switch, each of said pushbuttons being normally adapted. upon depression thereof to its inner extreme position to provide for operation of its associated switch to on position, means comprising a metal lever pivotally supported by said plate for oscillatory movement in a plane parallel thereto, said metal lever having an arm upstanding from each end thereof, spring means for biasing said lever to a given extreme position wherein one arm thereof underlies one of said pushbuttons, said last mentioned arm having a cam surface engageable by said last mentioned pushbutton to oscillate said lever against the bias of said spring means into underlying relation to the other pushbutton when the latter is in its upper extreme position, said lever arms thus acting to permit depression of one or the other of said pushbuttons while positively preventing simultaneous depression of both pushbuttons to their inner extreme positions.

11. In combination, a relatively long, flat sheet metal plate having a pair of longitudinally spaced substantially circular openings formed therein, a pair of doub1e-pole, two-position, snap switches of like form secured to said plate in tandem relationship to each other, said switches having insulating base portions arranged at the rear face of said plate and pivotally supported operating levers extending upwardly through said plate openings and having portions thereof exposed at the front face of said plate, a pushbutton pivotally connected with each lever in longitudinally offset relation to the point of pivotal support of the latter, said switches being of the spring toggle type whereby the same are normally biased individually to either the on or the off position thereof depending upon the positions of their respective levers, overpowering spring means associated with each pushbutton to normally bias the same and its associated lever to a given extreme position to provide for off positioning of its respective switch, each of said pushbuttons being normally adapted upcrn manual depression thereof to its inner extreme position to provide for operation of its associated switch to on position, means for mechanically interlocking said pushbuttons to positively prevent simultaneous depression thereof to their inner extreme positions, means comprising a longitudinally divided metal casing providing an enclosure for said pair of switches, said casing having a pair of openings in one face thereof through which said pushbuttons project, and said casing having an opening in an end thereof to provide for entrance of a cable or conductor, said cable being adapted to suspend said casing and the switches carried by the latter.

12. A pushbutton reversing control station for hoist motors and the like, comprising, in combination, a relatively long, fiat sheet metal plate having a pair of longitudinally spaced openings formed therein, a pair of multi-pole switches of like form secured to said plate in tandem relationship to each other, said switches having insulating base portions arranged at the rear face of said plate and pivotally supported operating levers extending upwardly through said plate openings and having portions thereof exposed at the front face of said plate, a pushbutton pivotally connected with each lever in longitudinally offset relation to the point of pivotal support of the latter, spring means associated with each pushbutton to normally bias the same to a given extreme position forwardly of the front face of said plate, means cooperatively associated with said pushbuttons to positively prevent simultaneous depression thereof to their inner extreme positions, said switches having a plurality of bottomwiring terminal members positioned at each end of the respective insulating base portions thereof, and means for electrically connecting the longitudinally adjacent pairs of terminal members at the adjacent ends of said insulating base portions, said means including means for detachably connecting circuit wires respectively common to said adjacent pairs of terminal members.

13. As an article of manufacture, a manually operable switch assembly of the pushbutton type comprising, a relatively long, flat sheet metal plate, a pair of multi-pole switches of like form secured to said plate, said switches having pivoted operating levers extending upwardly beyond said plate, a pushbutton pivotally connected with each lever in offset relation to the point of pivotal support of the latter, spring means associated with each pushbutton to normally bias the same to a given extreme position forwardly of the front face of said plate, and means cooperatively associated with said pushbuttons to positively prevent simultaneous depression thereof to their inner extreme positions, for the purpose set forth.

GEORGE J. MEUER. 

